# bad - four spaces
  def some_method
    do_something
  end

  # good
  def some_method
   do_something
  end

  $ git config --global core.autocrlf true

 # bad
  puts 'foobar'; # superfluous semicolon

  puts 'foo'; puts 'bar' # two expression on the same line

  # good
  puts 'foobar'

  puts 'foo'
  puts 'bar'

  puts 'foo', 'bar' # this applies to puts in particular

 # bad
  class FooError < StandardError
  end

  # okish
  class FooError < StandardError; end

  # good
  FooError = Class.new(StandardError)

# bad
  def too_much; something; something_else; end

  # okish - notice that the first ; is required
  def no_braces_method; body end

  # okish - notice that the second ; is optional
  def no_braces_method; body; end

  # okish - valid syntax, but no ; make it kind of hard to read
  def some_method() body end

  # good
  def some_method
   body
  end

  # good
  def no_op; end

  sum = 1 + 2
  a, b = 1, 2
  1 > 2 ? true : false; puts 'Hi'
  [1, 2, 3].each { |e| puts e }

  # bad
  e = M * c ** 2

  # good
  e = M * c**2

  # good - space after { and before }
  { one: 1, two: 2 }

  # good - no space after { and before }
  {one: 1, two: 2}

  # good - no spaces
  "string#{expr}"

  # ok - arguably more readable
  "string#{ expr }"

  some(arg).other
  [1, 2, 3].length

  ! 之后没有空格 .

  # bad
  ! something

  # good
  !something

# bad
  case
   when song.name == 'Misty'
    puts 'Not again!'
   when song.duration > 120
    puts 'Too long!'
   when Time.now.hour > 21
    puts "It's too late"
   else
    song.play
  end

  # good
  case
  when song.name == 'Misty'
   puts 'Not again!'
  when song.duration > 120
   puts 'Too long!'
  when Time.now.hour > 21
   puts "It's too late"
  else
   song.play
  end

  case
  when song.name == 'Misty'
   puts 'Not again!'
  when song.duraton > 120
   puts 'Too long!'
  when Time.now > 21
   puts "It's too late"
  else
   song.play
  end

  # bad - pretty convoluted
  kind = case year
  when 1850..1889 then 'Blues'
  when 1890..1909 then 'Ragtime'
  when 1910..1929 then 'New Orleans Jazz'
  when 1930..1939 then 'Swing'
  when 1940..1950 then 'Bebop'
  else 'Jazz'
  end

  result = if some_cond
   calc_something
  else
   calc_something_else
  end

  # good - it's apparent what's going on
  kind = case year
      when 1850..1889 then 'Blues'
      when 1890..1909 then 'Ragtime'
      when 1910..1929 then 'New Orleans Jazz'
      when 1930..1939 then 'Swing'
      when 1940..1950 then 'Bebop'
      else 'Jazz'
      end

  result = if some_cond
        calc_something
       else
        calc_something_else
       end

  # good (and a bit more width efficient)
  kind =
   case year
   when 1850..1889 then 'Blues'
   when 1890..1909 then 'Ragtime'
   when 1910..1929 then 'New Orleans Jazz'
   when 1930..1939 then 'Swing'
   when 1940..1950 then 'Bebop'
   else 'Jazz'
   end

  result =
   if some_cond
    calc_something
   else
    calc_something_else
   end

 def some_method
   data = initialize(options)

   data.manipulate!

   data.result
  end

  def some_methods
   result
  end

 # bad - easier to move/add/remove parameters, but still not preferred
  some_method(
         size,
         count,
         color,
        )

  # bad
  some_method(size, count, color, )

  # good
  some_method(size, count, color)

 # bad
  def some_method(arg1=:default, arg2=nil, arg3=[])
   # do something...
  end

  # good
  def some_method(arg1 = :default, arg2 = nil, arg3 = [])
   # do something...
  end

  # bad
  result = 1 - 
       2

  # good (but still ugly as hell)
  result = 1 
       - 2

  long_string = 'First part of the long string' 
         ' and second part of the long string'

# bad - need to consult first line to understand second line
    one.two.three.
     four

    # good - it's immediately clear what's going on the second line
    one.two.three
     .four

  # bad - need to read ahead to the second line to know that the chain continues
    one.two.three
     .four

    # good - it's immediately clear that the expression continues beyond the first line
    one.two.three.
     four

 # starting point (line is too long)
  def send_mail(source)
   Mailer.deliver(to: 'bob@example.com', from: 'us@example.com', subject: 'Important message', body: source.text)
  end

  # bad (double indent)
  def send_mail(source)
   Mailer.deliver(
     to: 'bob@example.com',
     from: 'us@example.com',
     subject: 'Important message',
     body: source.text)
  end

  # good
  def send_mail(source)
   Mailer.deliver(to: 'bob@example.com',
           from: 'us@example.com',
           subject: 'Important message',
           body: source.text)
  end

  # good (normal indent)
  def send_mail(source)
   Mailer.deliver(
    to: 'bob@example.com',
    from: 'us@example.com',
    subject: 'Important message',
    body: source.text
   )
  end

 # bad - single indent
  menu_item = ['Spam', 'Spam', 'Spam', 'Spam', 'Spam', 'Spam', 'Spam', 'Spam',
   'Baked beans', 'Spam', 'Spam', 'Spam', 'Spam', 'Spam']

  # good
  menu_item = [
   'Spam', 'Spam', 'Spam', 'Spam', 'Spam', 'Spam', 'Spam', 'Spam',
   'Baked beans', 'Spam', 'Spam', 'Spam', 'Spam', 'Spam'
  ]

  # good
  menu_item =
   ['Spam', 'Spam', 'Spam', 'Spam', 'Spam', 'Spam', 'Spam', 'Spam',
    'Baked beans', 'Spam', 'Spam', 'Spam', 'Spam', 'Spam']

  # bad - how many 0s are there?
  num = 1000000

  # good - much easier to parse for the human brain
  num = 1_000_000

  # bad
  == begin
  comment line
  another comment line
  == end

  # good
  # comment line
  # another comment line